Use newer OpenSSL version in ports, otherwise spamassassin doesn't compile:
echo WITH_OPENSSL_PORT=yes > /etc/make.conf
Fixed in iRedMail development edition moment ago.
fix apache startup after running iRedmail.sh:
cd /usr/ports/devel/apr1
...
selected: ipv6, devrandom, bdm, gbdm, mysql and ssl
iRedMail-0.9.4 has them all selected. The point is, what's wrong with Apache (with default iRedMail settings)?
2016-02-24 04:34:00.496 sogo-tool[98502:101326] Table 'sogo.sogo_sessions_folder' doesn't exist
/usr/local/GNUstep/Local/Tools/Admin/sogo-tool: Uncaught exception ExecutionFailed, reason: Table 'sogo.sogo_sessions_folder' doesn't exist
A known "issue/bug" of SOGo. Restarting sogo service will trigger sogo to create required sql tables, that fixes it.
[Wed Feb 24 11:04:48.728943 2016] [wsgi:error] [pid 97025] [client 192.168.1.215:54603] Truncated or oversized response headers received from daemon process 'iredadmin': /usr/local/www/iredadmin/iredadmin.py
Could you please post full/context log? This log cannot help figure out the cause.